I just switched from a WSM2 to a RM...
I have used it in practice and 1 match. It fit my aluminum grip Bedell without modification. I like it much better for several reasons:
When locked, its LOCKED (can move slightly but the gun isnt coming out unless you unlock it)
Even when not locked, it is very secure and unless the gun is moved upward it isn't comin out.
When you do draw (correctly) it is smooth as butter.
My only complaints are that I don't like the big tension knob (gonna order the smaller one) and that if when you draw you dont come straight up it binds and wont come out until you do come straight up for the first part of the draw, but that is an issue with my draw and not the holster.
Overall, a great holster. Smooth, Fast and Secure